This invention relates to a hydraulic damper of the adjustable damping force type.
One prior art hydraulic damper of adjustable damping force type includes a piston working in a cylinder and partitioning the interior of the cylinder into two liquid chambers, a piston rod with one end being connected to the piston and the other end extending to the outside of the cylinder, a liquid passage formed in the piston rod for connecting the two liquid chambers, an opening adjusting member movably disposed in the liquid passage for selectively adjusting the effective passage area of the liquid passage between at least three different passage area conditions, and an actuating device for reciprocatingly moving the adjusting member between two extreme positions and one or more intermediate positions corresponding to respective passage area conditions.
The actuating device is required to move the adjusting member quickly and accurately to respective passage area conditions. Particularly, it is very difficult to stop the adjusting member at intermediate positions.